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Types of Anti-Seizure Medications (ASMs)

Medications

As you will read on this page, there are many types of Anti-Seizure Medications (ASMs). It is important to remember that epilepsy is a very individual condition and finding the right treatment for a person's seizures can be a trial and error process for a treating clinician. 

This page has been designed to give brief information on the currently available ASMs; what type of seizures they may primarily be used in the treatment of; and possible side effects associated with each medication. It is important to note that all medications carry some form of risk, and the possible side effects listed below does not mean that a person will experience all those side effects. Just like epilepsy being an individual condition, how a medication works (and the experience of side effects) is also an individual experience. 

Further information on types of seizures can be found by visiting the 'Epilepsy Explained' section of our website, while you will also find further information on side effects and why it is important to report them by visiting the 'Treatment' section of our website. 


  • Brand (Generic): Ativan (Lorazepam)
  • Used for: Monotherapy/add-on for all seizure types
  • Possible side effects: Drowsiness, light-headedness

  • Brand (Generic): Brivlact (Brivaracetam)
  • Used for: Add-on for focal/partial seizure with or without secondary generalisation
  • Possible side effects: Sedation, dizziness, nausea, balance problems, depression, changes in mood and behaviour 

  • Brand (Generic): Diacomit (Stiripentol)
  • Used for: Add-on for tonic clonic seizures in children with severe myoclonic epilepsy of infancy/Dravet Syndrome
  • Possible side effects: Reduced appetite, weight loss, insomnia. aggression, nausea, rash, fatigue

  • Brand (Generic): Diamox (Acetazolamide)
  • Used for: Has a role in epilepsy linked to menstruation. It can also be used with other Anti Seizure Medications for all seizure types. 
  • Possible side effects: Nausea, vomiting, headache, dizziness, increased urine output. 

  • Brand (Generic): Epanutin (Phenytoin) 
  • Used for: Monotherapy/Add-on for all forms of seizure types expect absence seizures. Blood level monitoring is important. 
  • Possible side effects: Gastro intestinal disturbance, skin rash, drowsiness, constipation, tremor, unsteadiness and slurred speech. Coarsening of facial features, overgrowth of gums and acne may be a side effect from prolonged therapy. 

  • Brand (Generic): Epilim, Epilim chrono, Epilim chronosphere (Sodium Valproate)
  • Used for: Monotherapy/Add-on for all forms of seizure types.
  • Possible side effects: Drowsiness and tremor are infrequent side effects. Hair loss occurs in some people and on occasions excessive weight gain may occur. However, these effects are usually reversible if dose is reduced.  This drug should not be used in women of childbearing age unless no other drug is effective. For more on this, please visit the 'Valproate' section of our website. 

  • Brand (Generic): Epistatus/Buccolam (Buccal Midazolam) 
  • Used for: For all seizure types that are prolonged or clustered. 
  • Possible side effects: Drowsiness. 

  • Brand (Generic): Felbatol (Felbamate) 
  • Used for: Add-on for all seizure types which have failed all other ASMs. Used under strict conditions. 
  • Possible side effects: Constipation, diarrhoea, difficulty sleeping, dizziness, headache, loss of appetite, nausea, vomiting. Liver failure is a rare risk. 

  • Brand (Generic): Frisium (Clobazam)
  • Used for: Add-on for all seizure types
  • Possible side effects: Drowsiness, light headedness, confusion, gastro-intestinal disturbances.  

  • Brand (Generic): Fycompa (Perampanel)
  • Used for: Add-on treatment for focal/partial seizures with or without secondary generalisation. 
  • Possible side effects: Drowsiness, nausea, balance problems, back pain, dizziness, mood and behaviour changes, weight gain, headache, double vision. 

  • Brand (Generic): Gabitril (Tiagabine) 
  • Used for: Add-on treatment for focal/partial seizures with or without secondary generalisation. 
  • Possible side effects: Diarrhoea, dizziness, tiredness, nervousness, tremor, impaired concentration, low mood. 

  • Brand (Generic): Inovelon (Rufinamide)
  • Used for: Add-on treatment of seizures in Lennox-Gastaut syndrome
  • Possible side effects: Nausea, vomiting, diarrhoea, weight loss, abdominal pain, drowsiness, insomnia, fatigue, rash. 

  • Brand (Generic): Keppra (Levetiracetam) 
  • Used for: Monotherapy and add-on treatment of all seizure types 
  • Possible side effects: Nausea, vomiting, diarrhoea, abdominal pain, weight changes, cough, drowsiness, dizziness, headache, low mood. 

  • Brand (Generic): Lamictal (Lamotrigine) 
  • Used for: Monotherapy and add-on treatment for all seizure types. 
  • Possible side effects: Gastro intestinal disturbance, skin rash, drowsiness, double vision, dizziness and headache, insomnia. 

  • Brand (Generic): Lyrica (Pregablin)
  • Used for: Add-on therapy for focal/partial seizures with or without secondary generalisation
  • Possible side effects: Dry mouth, constipation, nausea, vomiting, weight gain, drowsiness, dizziness, changes in mood, attention difficulties. 

  • Brand (Generic): Mysoline (Primidone)
  • Used for: Monotherapy/add-on for all seizure types expect absence seizures. 
  • Possible side effects: Nausea, visual disturbances, unsteadiness and drowsiness may occur initially but sedation and slowing of cognitive performance may persist. 

  • Brand (Generic): Neurontin (Gabapentin)
  • Used for: Monotherapy and add-on treatment of focal/partial seizure with or without secondary generalisation. 
  • Possible side effects: Gastro intestinal disturbance, diarrhoea, dry mouth, drowsiness, dizziness, headache, fatigue, weight gain. 

  • Brand: Nitrazepam 
  • Used for: Infantile Spasms
  • Possible side effects: Confusion, memory loss, muscle weakness, tremor. 

  • Brand (Generic): Phenobarbitone (Phenobarbital) 
  • Used for: Monotherapy/add-on for all forms of seizure types except absence seizures. 
  • Possible side effects: Nausea, unsteadiness and drowsiness may occur initially but sedation and slowing of cognitive performance may occur. 

  • Brand (Generic): Rivotril (Clonazepam)
  • Used for: Add-on for all seizure types. 
  • Possible side effects: Drowsiness, fatigue, dizziness, restlessness. 

  • Brand (Generic): Sabril (Vigabatrin) 
  • Used for: Must be initiated and supervised by appropriate specialist, add-on treatment of partial seizures with or without secondary generalisation. Monotherapy in West Syndrome. 
  • Possible side-effects: Drowsiness, nausea, behaviour, mood changes, visual field defects, psychotic reactions have been reported. 

 

  • Brand (Generic): Tegretol, Tegretol SR (Carbamazepine)
  • Used for: Monotherapy/Add-on for partial seizures and secondary generalised tonic-clonic seizures, generalised tonic-clonic seizures. 
  • Possible side-effects: Nausea, vomiting, dizziness, drowsiness, skin rash, double vision, unsteadiness. 

  • Brand (Generic): Topamax (Topiramate) 
  • Used for: Monotherapy and add-on treatment of generalised tonic-clonic seizures, or of focal/partial seizures with or without secondary generalisation. 
  • Possible side-effects: Nausea, abdominal pain, diarrhoea, dry mouth, taste disturbance, weight loss, headache, fatigue, dizziness, word finding difficulties, pins and needles in hands and feet, kidney stones. Use of Topamax in women of childbearing age is currently being further investigated following recent research - please visit the Topiramate section of our website for further information. 

  • Brand (Generic): Trileptal (Oxcarbazepine)
  • Used for: Monotherapy and add-on treatment of focal/partial seizures with or without generalised tonic-clonic. 
  • Possible side effects: Nausea, vomiting, constipation, diarrhoea, abdominal pain, dizziness, headache and drowsiness, skin rash. 

  • Brand (Generic): Valium/Stesolid (Rectal Diazepam) 
  • Used for: Emergency rescue treatment for seizures that are prolonged or clustered. 
  • Possible side effects: Drowsiness, tolerance of drug. 

  • Brand (Generic): Vimpat (Lacosamide) 
  • Used for: Add-on therapy in the treatment of partial seizures with or without secondary generalisation.
  • Possible side effects: Nausea, vomiting, dizziness, headache, constipation, depression, double vision, drowsiness. 

  • Brand (Generic): Zarontin, Emeside (Ethosuximide) 
  • Used for: Typical absence seizures, it may also be used in atypical absence seizures. 
  • Possible side effects: Gastro intestinal disturbance, nausea, vomiting, headache, fatigue, dizziness, weight loss. 

  • Brand (Generic): Zebinix (Eslicarbasepine Acetate)
  • Used for: Add-on treatment in adults with focal/partial seizures, with or without secondary generalisation. 
  • Possible side effects: Dizziness, sleepiness, nausea, headache. More serious side effects include rash and liver problems. 

  • Brand (Generic): Zonegran (Zonisamide)
  • Used for: Add-on treatment for drug-resistant focal/partial seizures, with or without secondary generalisation. 
  • Possible side effects: Nausea, diarrhoea, abdominal pain, weight loss, drowsiness, kidney stones, dizziness, confusion, irritability, skin rash.